Installing window and door trim requires care in making the miter cuts at the corners, and further the set back of the trim from the edge of the opening requires care in order to have uniform mounting of the trim boards.
This present invention discloses jig guide apparatus for marking or scribing trim board for subsequent corner miter cuts of the trim board, and to have a uniform set back of the trim board from the window or door opening, on all sides of a window/door opening.